The present invention relates to a microtitration plate.
Microtitration plates are used for most varied microbiological, cell-breeding, and immunological techniques. In particular, microtitration plates are employed for the PCR (polymerase-chain-reaction) or the breeding of microorganisms or cells.
Microtitration plates have already been known which have a frame with a plate to which a multiplicity of vessels are fixed which have a receiving portion protruding from the underside of the plate and are accessible from the upper surface of the plate through apertures. The vessels are also referred to as “wells”. The current 96-type microtitration plates have 8×12=96 vessels in rows and columns. However, microtitration plates having a larger number of vessels are used more and more.
Single-component microtitration plates in polystyrene are unsuitable for the PCR, particularly because the softening temperature of this plastic (about 85° C.) is exceeded during the PCR.
Single-component microtitration plates in polypropylene generally are adapted to be used for the PCR. However, they are flexurally soft, tend to be distorted, are uneven and are manufactured only at large tolerances and undergo large tolerance variations when in use. Specifically, they are not particularly suited for being handled by automatic devices because their softness makes it difficult for automatic devices to grip them. Further, their low dimensional stability may have the consequence that the proportioning needles will contact the walls while being introduced into the vessels. Furthermore, heat transfer into the walls is poor because the thick walls of the vessels impede it, which is adverse to temperature regulation and the length of cycle times during the PCR.
It is particularly in breeding microorganisms or cells that the sample requires sufficient oxygen supply. In the 96-type microtitration plates, this can be ensured because of the relatively large apertures of the vessels. However, in microtitration plates having a larger number of vessels, e.g. 384, oxygen supply may be impaired very much by the reduced cross-sections of the apertures. In addition, it would be desirable to ensure oxygen supply even if the apertures are closed in order to avoid transversal contaminations between the samples of various vessels.
Attempts to avoid transversal contaminations are also made in other applications of microtitration plates. To this end, there are sealing foils which are welded onto the upper surface of the microtitration plate and have to be released again if an access is required to the contents of the vessels. In addition, there are rubber mats which have cones at their underside in order to sealingly engage the apertures of the vessels when placed on the microtitration plate. Further, there are plastic strips which are designed with stoppers at their underside in order to be forced into the apertures of a row of vessels in the microtitration plate.
The known sealing methods are complicated in use and do not satisfy the increased requirements to tightness.
Therefore, it is the object of the invention to provide a microtitration plate having more favourable characteristics in use.
In addition, a technique for the manufacture of the microtitration plate will be provided.